iconify/iconify-icon-demo/nuxt3-demo/nuxt.config.ts

import { defineNuxtConfig } from 'nuxt';

// https://v3.nuxtjs.org/docs/directory-structure/nuxt.config
export default defineNuxtConfig({
	vue: {
		compilerOptions: {
			isCustomElement: (tag) => tag === 'iconify-icon',
		},
	},
});